The overall objective of this project is to elucidate the molecular mechanisms involved in the regulation of the growth and function of adrenocortical cells. It is proposed to investigate the specific biochemical events in the cell cycle which are affected by adrenal growth factors and ACTH. The molecular mechanism of induction and maintenance of the steroidogenic capacity of adrenocortical cells will be investigated. The properties of the adrenocortical cell surface as well as the cytoskeleton and the changes induced by hormones will be examined. It is also proposed to investigate the proliferation and function of normal and tumor Leydig's cells.